How to

How to run quality control on merch — before, during and after production

Quality control on corporate merch is not a single end-of-line event: it is a four-point system — pre-production, DUPRO, PSI and reception — with agreed AQL levels, defect classification and signed per-lot reports, aligned to NOM-050 and to international retail standards.

See the 7 steps Templates and references

What quality control on merch is (and is not)

Quality control on corporate merch in Mexico is misunderstood when it is reduced to a final inspection. A polo with the wrong shade, a notebook with a misaligned logo, a tumbler with a leaking lid: each of these defects originates at a different moment in the process and is prevented by a different control point. Trying to solve everything in the final inspection means accepting an 8 % to 15 % reject rate and significant operational pain.

The correct framework is four points: pre-production (PP), during-production inspection (DUPRO), pre-shipment inspection (PSI) and customer-side reception. Each point has its own objective, its own agreed AQL level, its own checklist and its own sign-off. Corp-Merch.MX has run this framework for four years across 14 audited workshops and 480 active SKUs; the customer-side defect rate stays below 1.5 % on regular programs and below 3 % on tight-deadline campaigns.

AQL (Acceptable Quality Level) is the percentage of defects the customer is willing to accept as a maximum. For standard promotional merch the working AQL is 2.5 under normal inspection; for premium or export merch it drops to 1.5 or 1.0. For programs with child end users the AQL is 1.0 on critical defects (LFPDPPP, choking hazard). Setting the AQL before the quote avoids disputes at the end of the lot.

Defect classification follows the international standard: critical (safety, incorrect regulatory information, recall risk), major (visible defect affecting use or brand perception), minor (visible defect not affecting use). Each level has its own acceptance criterion. A polo with the wrong size is a major defect; a polo with the right size but a loose 2 mm thread is a minor defect.

The Mexican regulatory framework is clear on some points and opaque on others. NOM-050-SCFI-2004 mandates composition labelling, country of origin and care instructions. PROFECO regulates advertising claims, including those on packaging. LFPDPPP applies if the program captures personal data via QR. Quality control does not replace regulatory compliance, but it is the mechanism that catches issues before they leave the workshop.

Before production starts, three documents must be signed by workshop and customer: the technical specification with tolerances, the inspection plan with its control points, and the catalogue of critical, major and minor defects. Without these three signed documents, quality control rests on goodwill alone.

The 7 steps of quality control

  1. Sign the technical specification with tolerances — for each piece: dimensions, weight, colour (with accepted ΔE), print or embroidery type, logo position, finishes, materials, packaging. The spec is annexed to the lot contract and signed by workshop and customer. Corp-Merch.MX uses a template with 38 fields per SKU.
  2. Define the inspection plan and control points — four points: PP on materials arrival, DUPRO at 30 %-50 % of the lot, PSI at 100 % before shipment, reception at customer warehouse. Each point has owner, checklist, sample size and AQL criterion.
  3. Hire a third-party inspector or train an internal one — for premium or export programs, a third-party inspector (SGS, Bureau Veritas, Intertek) is worth the cost. For in-house programs with limited budget, an internal inspector trained in AQL works. Minimum training is 16 hours with an exam.
  4. Run the pre-production inspection (PP) — verify that incoming raw material matches the spec: fabric colour, gauge, composition, ink batch, thread gauge. Any deviation is reported before the first piece is cut.
  5. Run the during-production inspection (DUPRO) — at 30 %-50 % of the lot, inspect between 30 and 125 pieces (per AQL table) to detect systematic defects: broken print pattern, palette drift, embroidery tone. If defects exceed AQL, the lot is stopped and corrected before continuing.
  6. Run the pre-shipment inspection (PSI) — at 100 % of the finished lot, a random sample is drawn per AQL table (level II normal), every spec item is checked, and the report is signed. If the lot passes PSI, it ships. If not, it returns to production or rework.
  7. Close with reception inspection and signed per-lot report — on arrival at customer warehouse, repeat the inspection with the same AQL table. The signed per-lot report is archived for five years and stays available for internal or SAT audit.

Common mistakes that cost money and reputation

The first mistake is signing the technical specification after the first piece has been produced. The spec is the foundation of quality control; signed late, it no longer serves to reject the lot because the lot is already made. The tolerance conversation with each workshop happens before cutting the fabric.

The second mistake is confusing inspection with control. Inspection is the snapshot; control is the system that prevents the defect from appearing in the first place. A program that only inspects at the end pays the scrap cost; a program with pre-production and DUPRO control pays less and delivers better.

The third mistake is not having a signed defect catalogue. Without a catalogue, the discussion of whether a defect is critical, major or minor becomes subjective and the workshop and customer argue case by case. The catalogue signed up front eliminates the ambiguity.

The fourth mistake is skipping DUPRO to save time. During-production inspection catches systematic defects that PSI misses because they are already mixed into the rest of the lot. Without DUPRO, 5 %-10 % of the lot can come out defective without PSI noticing.

The fifth mistake is not measuring defect rate per supplier and per SKU. Without measurement, there is no way to know which workshop performs better or which piece is more problematic. Corp-Merch.MX publishes the monthly defect-rate ranking per workshop so the customer can decide where to buy.

The sixth mistake is mixing the quality report with the invoice. Quality is signed separately from payment; if mixed, the customer pays first and argues quality later, with no leverage. Quality is signed before the CFDI 4.0 and the final payment.

Templates, references and tools

Technical specification: document with 38 fields per SKU: dimensions, weight, material, colour (with ΔE ≤ 2 against Pantone), print or embroidery type, logo position, finishes, packaging. Signed by workshop and customer before production. Corp-Merch.MX ships a ready-to-use template.

Inspection plan: four points (PP, DUPRO, PSI, reception), with owner, checklist, sample size per AQL table level II, acceptance and rejection criteria. Annexed to the lot contract.

Defect catalogue: classification by level (critical, major, minor) with visual examples: open seams, stains, print misalignment, wrong shade. Signed by both parties at program start.

AQL tables: ISO 2859-1 standard, inspection level II, AQL 2.5 (standard), 1.5 (premium), 1.0 (children or critical). Sample size and acceptance number per lot size.

Regulatory references: NOM-050-SCFI-2004 (textile labelling); LFPDPPP (personal data in QR); PROFECO (advertising without misleading claims); ISO 2859-1 (AQL); ASTM D3990 (textile defect terminology).

Third-party inspectors in Mexico: SGS, Bureau Veritas, Intertek, TÜV Rheinland, Control Union. For export also PSI-MX, Eurofins Servicios and Applus+. Cost per inspector-day between USD 250 and USD 450 plus expenses.

Suggested cadence: day 1, signed technical spec; day 3, agreed defect catalogue; day 5, active inspection plan; day 7-10, first PP inspection; day 14-21, DUPRO with signed report; day 28-32, PSI with shipment authorisation; day 33-35, customer reception with signature. For urgent lots, DUPRO and PSI can be compressed with double shift at the workshop.